2 Answers
2

As @poige and @Pawel said, you most likely have a corrupted filesystem and you need to somehow fix it.

HOWEVER, if you have anything important stored on your disk, DO NOT just blindly run fsck. Before proceeding make sure you have decent backups and copy all the data from your disk to a brand new hard drive.

Such errors causing freezes do not just appear out of the blue; it might very well be your HD is dying and fsck would make more harm than good.